Improvement in elevators



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Improvement in Elevators. N0. 131,170. Patented Sep.10,1872.

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DAVID KNOYVLES, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN ELEVATORS.

Specification forming part of Letters Patent No. 131,170, dated September 10, 1872.

Specification describing certain Improvements in Elevators, invented by DAVID KNOWLES, of the city and county of Philadelphia and State of Pennsylvania.

The first part of my invention relates to the combination of a shaft, weighted lever, cams, and clamp-boxes with the platform, its actuating rope and counterbalance, and iron guides in such a manner that the said cams and boxes will be caused to engage or bind against the iron guides to instantly arrest the descent of the platform should the actuating rope break. The object of this part of my invention is to dispense with the toothed or notched bars now employed, which, besides being expensive, are also liable to break, for want of elasticity, by the sudden shock when arresting the motion of the car. The second part of my invention relates to the arrangement of the gearing hoisting-drum and shifting-gear for producing a fast or slow motion of the platform; the object of which is to vary the speed of the same according to the weight of goods or articles upon it. The latter-part of my invention relates to the construction of a brake consisting of an eccentric, lever, and shoe, operating on the wheel-rope.

Figure 1 is a plan view of my improvement in elevators. Fig. 2 is a side elevation of the same. Fig. 3 is a detached view of the brake and rope-wheel partially broken. Fig. 4 is a sectional elevation of the platform and hoistin g-drum. Fig. 5 is a plan view of the under side of the platform.

A, Fig. 2, is the platform, on the under side of which are secured two clamp-boxes, B B, passing through the side of which is a shaft, 0, provided with a weighted lever, D, and on the ends with cams E E, as shown in Figs. 4 and 5. The wrought-iron guides F F, consisting of flat bars, are inserted edgewise into the guide-posts G and G, and are embraced on one side by the clamp-boxes B B and on the opposite side by the cams E E. At the upper part of the frame are placed two shives, H and H, which slide loosely upon a stationary rod, I. One of these shives, H, has passed over it the actuating rope J, leading from the hoisting-drum K, to the end of which is attached a weight, L, to counterbalance the weight of the platform. The lever D has attached to it one end of a wire-rope or cord, M, the opposite end of which is passed over a shive, N, set in the edge of the platform, and leads over the pulley H to the weight L, where it is secured. The shaft 0, Figs. 1, 2, and 4, carrying the spur-wheels P and' P and shive or drum K, is mounted in bearings supported on the crosspieces S S of the framing. These intermediate pieces permit a short shaft to be used, thereby saving material and, at the same time, increasing the strength of the various parts. The spur-wheels P and P and shive K are centered loosely on the shaft 0. The shive, being pro-- vided with lugs a a on its sides, operates as a clutch in connection with the gear-wheel P or P. The apparatus for shifting it consists of two bars, T T, provided with fingers which engage with the flanges. The said bars are connected by a cross-bar or rod, U, and are moved simultaneously by means of a lever, W, Figs. 1 and 2. The largest spur-wheel P, for the slow motion, meshes into apinion, X, fixed on the shaft Y of the hoisting-wheel Z; and the smaller gear-wheel P for the fast motion, meshes into a pinion, X, on the same shaft. The gear-wheels P and P are placed at such a distance apart that the shive K is always engaged with either one of them.

Fig. 3 shows a friction-brake used to check the downward movement of the platform. It consists of an eccentric, 12, secured on a shaft, 0, on the outer end of which is placed a lever or pulley for operating it. Resting on the said eccentric is an iron strap or shoe, B, which is forced against the edge of the hoisting-wheel Z by a partial rotation of the eccentric to in crease or diminish the friction to stop or check the descent of the platform, as required.

When from any cause the hoisting-rope should be broken,.the weight of the platform pressing on'the cord M will draw the weighted lever D over in the position shown in Fig. 4, thereby causing a partial rotation of the shaft 0, and cause the cams E E to press against and bind the clamp-boxes firmly against the guide-bars. These movements take place the instant the rope parts, or while it is yielding before complete rupture takes place. The platform may be stopped or held at any point in its ascent or descent by simply drawing upon the cord MI.

.I claim as my inirention- X X, substantially in the manner and for the 1. Thecombination,with ap1atform,itshoistpurpose described. ing-rope J, and counterbalance L, of a shaft, 0, 3. The combination, with the hoisting-wheel weighted lever D, clamp-boxes B B, cams E Z, of a frictional-brake, consisting substan- E, iron guides F F, rope M, and shives H, H, tially of the shaft 0, eccentric b, and shoe B,

and N, all operating substantially as "and for operating in the manner as herein set forth.

the purpose herein described. DAVID KNOWLES.

2. The combination of the shaft 0, supported in appropriate hearings on the cross-pieces S Witnesses:

S, and provided with gear-wheels P and P, ISAAC R. OAKFORD,

and shive K, with the shaft Y and gear-wheels WILLIAM H. OVERBEOK. 

